The present invention relates to a rigid resin mold that is merely called bried mold for preparing resin moldings. More particularly, the present invention relates to a method for producing a rigid resin mold that has high heat resistance, abrasion resistance and thermal conductivity and which is easy to handle in the process involving the steps of preparing two kinds of thermosetting resin compositions in a fluid state, mixing them, casting a molten resin, gelling the resin, and subsequently after-curing it at a higher temperature for the purpose of curing the same.
Conventionally, rigid resin molds are produced by curing, at ambient temperature, an epoxy resin which is mixed with a metal powder or fiber, a curing agent (e.g. tertiary amine or acid anhydride), and with a curing catalyst. In order to improve the limited resistance of epoxy resins to heat and moisture, the use of highly heat-resistant epoxy resins such as polyfunctional epoxy resins has been proposed. But such epoxy resins per se are very brittle and are unable to withstand the handling encountered in practical operations. In order to solve this problem, mixing a flexible materials in epoxy resins is essential, but then it is impossible to provide a product having adequately improved heat resistance.